Easy Upload Files During Checkout <= 3.0.0 - Missing Authorization

This exploitation research plan focuses on CVE-2025-62078, a Missing Authorization vulnerability in the "Easy Upload Files During Checkout" plugin.

Given the plugin's purpose—managing file uploads during the WooCommerce checkout process—the vulnerability likely resides in an AJAX handler designed for administrative configuration or file management that fails to verify the user's capabilities.

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1. Vulnerability Summary

• Vulnerability: Missing Authorization (Broken Access Control)
• Affected Component: AJAX handler(s) in easy-upload-files-during-checkout.
• Impact: An authenticated user with Subscriber-level permissions can execute functions intended for Administrators, potentially modifying plugin settings or accessing/manipulating uploaded files.
• Root Cause: The plugin registers AJAX actions via wp_ajax_{action} but the callback function lacks a current_user_can('manage_options') check.

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Method: POST
• Action (Inferred): Likely related to settings updates or file deletion. Common patterns in this plugin include actions like eufdc_save_settings, eufdc_update_options, or eufdc_delete_upload.
• Authentication: Subscriber-level (PR:L).
• Parameter: action, nonce (if required), and payload parameters (e.g., option_name, option_value).

3. Code Flow (Tracing Entry Points)

To identify the specific sink, the research must follow this flow:

1. Registration: Search for add_action( 'wp_ajax_... in the plugin directory.
2. Callback Identification: Identify the function name associated with the AJAX action.
3. Authorization Audit: Examine the callback function for the absence of:
   • current_user_can( 'manage_options' )
   • current_user_can( 'edit_posts' )
4. Action Logic: Determine what the function does (e.g., update_option(), wp_delete_post(), or unlink()).

4. Nonce Acquisition Strategy

If the vulnerable function uses check_ajax_referer() or wp_verify_nonce(), the nonce must be retrieved.

1. Find the Hook: Identify where the plugin enqueues its admin scripts (usually an admin_enqueue_scripts hook).
2. Identify JS Variable: Look for wp_localize_script().
   • Search Command: grep -r "wp_localize_script" .
3. Localization Key (Inferred): The plugin likely uses a global variable such as eufdc_vars, eufdc_params, or easy_upload_admin_nonce.
4. Extraction:
   • Create a Subscriber user and log in.
   • Navigate to a page where the plugin's script is loaded (e.g., the WooCommerce account page or a plugin-specific settings page if accessible).
   • Use browser_eval to extract the nonce:

     // Example (adjust based on grep results)
     window.eufdc_admin_data?.nonce || window.eufdc_params?.ajax_nonce
     

5. Exploitation Strategy

The goal is to demonstrate unauthorized modification of plugin settings.

1. Step 1: Identify Target Action: Use grep -rn "wp_ajax_" . to find all registered AJAX actions.
2. Step 2: Check for Missing Auth: Inspect the callback functions. Look for one that calls update_option or modifies files without a capability check.
3. Step 3: Craft Payload:
   • If the target is eufdc_save_settings, the payload might look like:
     • action=eufdc_save_settings
     • eufdc_allowed_extensions=php,jpg,png (Attempting to escalate to RCE by allowing PHP uploads)
4. Step 4: Execute HTTP Request:

   # Example using http_request tool
   http_request(
       method="POST",
       url="http://localhost:8080/wp-admin/admin-ajax.php",
       headers={"Content-Type": "application/x-www-form-urlencoded"},
       body="action=[VULNERABLE_ACTION]&nonce=[NONCE]&[PARAM]=[VALUE]",
       cookies=[SUBSCRIBER_COOKIES]
   )
   

6. Test Data Setup

1. Users: Create a Subscriber user (user_login: 'victim', password: 'password').
2. WooCommerce Context: Ensure WooCommerce is active, as the plugin is a WooCommerce extension.
3. Plugin Settings: Note the original "Allowed File Types" or other settings in the plugin's admin panel to compare after the exploit.

7. Expected Results

• Response: The server returns a success code (e.g., {"success": true} or 1).
• State Change: An administrative setting (stored in wp_options) is modified despite the request originating from a Subscriber.

8. Verification Steps

After the HTTP request, use WP-CLI to verify the change:

# Check if the option was modified
wp option get [MODIFIED_OPTION_NAME]

# Example:
wp option get eufdc_settings

9. Alternative Approaches

• File Deletion: If an AJAX action handles file deletion (e.g., eufdc_remove_file), attempt to delete a file belonging to another user or a critical WordPress file by manipulating the file_id or path parameter.
• Information Disclosure: Look for AJAX actions that return sensitive data (like order details or file paths) without verifying that the requesting user owns the order.

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Audit Commands for the Agent

# 1. Find all AJAX handlers
grep -rn "wp_ajax_" .

# 2. Check for capability checks in those handlers
# Search for functions that DON'T contain 'current_user_can'
# Note: This requires manual inspection of the results from step 1
grep -rn "function " . | grep -A 10 "wp_ajax_"

# 3. Look for nonce localization
grep -rn "wp_localize_script" .